The present invention relates to the field of vehicles, and, more particularly, to vehicle warning systems.
Audible alert systems are used in various types of motor vehicles to alert pedestrians, bicyclists, etc. that a vehicle is backing up. This is important because the driver of the vehicle may not be able to see a person behind the vehicle if the person is in a so-called blind-spot. As such, these types of systems have become commonplace in large delivery trucks, heavy machinery, etc., where it may be particularly hard to see a person behind the vehicle.
Such systems are also becoming more popular in passenger vehicles, such as cars and small trucks. For example, U.S. Pat. No. 4,851,813 to Gottlieb discloses a combination back-up light and sound emitting device for an automotive vehicle including a housing having a base at one end and a socket at the other end. A light bulb is mounted in the socket of the housing and a sound emitting device is also mounted in the housing. The base may be inserted in a vehicle back-up bulb socket so that the sound emitting device and the light bulb are activated when the vehicle is in reverse.
Some back-up warning systems include a transceiver mounted on a rear end of a vehicle for detecting objects close to the vehicle while the vehicle is in reverse. For example, U.S. Pat. Nos. RE 34,773; 4,797,673; 4,864,298; and 5,028,920 to Dombrowski disclose a driver alerting device including a transceiver mounted on the rear end of a vehicle (e.g., on the bumper) that directs a wave output rearwardly from the vehicle. Return signals from objects within range of the transceiver are picked up by an antenna and supplied to the transceiver. Any resulting Doppler shift detected by the transceiver causes the transceiver to provide an audible alert within the passenger compartment.
The device may be connected for activation when the vehicle transmission is engaged in the reverse gear. One limitation of such devices is that they may be relatively bulky and require mounting on the back of the vehicle in a conspicuous location, such as on the vehicle""s bumper. Accordingly, these devices may be unsightly and they may also require screws, etc. to securely fasten the device to the vehicle. Thus, there may be a significant potential for damage to the vehicle during installation, and this process may take a substantial amount of time to complete. Further, such devices protrude from the bumper and may therefore be damaged or even knocked off the vehicle. Additionally, not all vehicles have a suitable mounting location for such devices.
A combined license plate frame and reverse warning alarm is illustrated in U.S. Pat. No. Des. 274,807 to Stansbury. As mentioned above, however, a reverse warning alarm may be inadequate to warn a driver of objects positioned rearward of the vehicle. A back-up sensor in a license plate holder is illustrated in U.S. Pat. No. Des 411,499 to Porter. Again, a back-up sensor alone may be insufficient to warn a driver of objects positioned rearward of the vehicle.
A license plate frame mount system offered by Sense Technologies, Inc. of Omaha, Nebr. under model designation 1500 includes license plate frame and a proximity sensor carried by the frame to provide a driver with an audible and visual warning of objects positioned behind the vehicle. The license plate frame mount, however, fails to include an external audible alarm, such as for warning pedestrians, for example, of the vehicle""s rearward motion. While the license plate frame mount by Sense Technologies can be used along with physically separate sound emitting devices described above, such a configuration may create installation complications, especially for routing wires between separate devices.
In view of the foregoing background, it is therefore an object of the invention to provide a backup warning system that is relatively easy to install and that provides warnings both internal to the vehicle and external from the vehicle.
This and other objects, features, and advantages in accordance with the present invention are provided by a back-up warning system for a vehicle that includes a license plate holder; a housing carried by the license plate holder; and a proximity sensor and an external audible indicator carried by the housing. More particularly, the back-up warning system may include a back-up lighting circuit that is selectively powered upon selection of a reverse transmission position. The license plate holder may include a generally rectangular body portion with an opening therein to mount and display the license plate and at least one bracket portion connected to the body portion for facilitating mounting of the license plate holder to the rear of the vehicle.
The back-up warning system may further include the housing connected to the license plate holder. The external audible indicator may be carried by the housing and connected to the back-up lighting circuit to be powered in parallel therewith for generating an external audible indication based upon selection of the reverse transmission position. The proximity sensor is also carried by the housing for sensing proximity of an object positioned rearward of the license plate holder.
An internal indicator may be positioned within the vehicle and cooperate with the proximity sensor to generate an indication of proximity of the object to the license plate holder. More specifically, the vehicle may include a vehicle passenger compartment and the internal indicator may be positioned within vehicle passenger compartment. The internal indicator may be a visual warning indicator. The vehicle may also include a rearview mirror, and the visual warning indicator may be carried by the rearview mirror.
The back-up warning system may also include a wireless communications link connecting the proximity sensor and the internal indicator. The wireless communications link may include a wireless transmitter connected to the proximity sensor and a wireless receiver within the vehicle and connected to the internal indicator. The external audible indicator may be connected to the proximity sensor and generate an audible indication relating to proximity of the object to the license plate holder. Alternately, the external audible indicator may provide a constant warning sound, not based on proximity.
The proximity sensor may be provided by a radar sensor. The back-up warning system may further include sensing circuitry carried by the proximity sensor. The sensing circuitry may include a signal emitter for emitting signals, and a collector for collecting reflected signals from the object positioned rearward of the license plate holder.
A method aspect of the invention is for making a back-up warning system for a vehicle having a back-up lighting circuit selectively powered upon selection of a reverse transmission position. The method may include providing a license plate holder and a housing connected thereto, and positioning an external audible indicator in the housing. The method may also include connecting the external audible indicator in parallel to the back-up lighting circuit for generating an external audible indication based on selection of the reverse transmission position, and positioning a proximity sensor in the housing for sensing objects positioned rearward of the license plate holder. The method may further include positioning an internal indicator within the vehicle passenger compartment to cooperate with the proximity sensor and generating an indication of proximity of an object to the license plate holder.